Tiffany Porter of Britain falls after competing in the women's 100 metres hurdles final during the 15th IAAF World Championships at the National Stadium in Beijing, China August 28, 2015. (Photo by David Gray/Reuters)

Second placed Zhang Guowei of China gestures as he celebrates after winning silver in the men's high jump final during the 15th IAAF World Championships at the National Stadium in Beijing, China, August 30, 2015. (Photo by Dylan Martinez/Reuters)

Genzebe Dibaba of Ethiopia competes in the women's 1500m semi-final during the 15th IAAF World Championships at the National Stadium in Beijing, China August 23, 2015. (Photo by Lucy Nicholson/Reuters)

Australian World War Two veterans place crosses and flags at graves before attending the French-British ceremony at the British War cemetery in Bayeux, June 6, 2014. REUTERS/Leon Neal/Pool

A TV cameraman drives into Usain Bolt of Jamaica after the men's 200m final during the Beijing 2015 IAAF World Championships at the National Stadium, also known as “Bird's Nest”, in Beijing, China, 27 August 2015. Bolt won the race. (Photo by Rolex Dela Pena/EPA)

Mom dressed as Santa and a boy dressed as Santa's helper posing under the water in the pool on December 15, 2016 in Odessa, Ukraine. (Photo by Andrey Nekrasov/Barcroft Images)

A sand carver works on a sculpture during the Sand Sculpture Festival “Dreams” in Ostend, Belgium on June 18, 2019. (Photo by Yves Herman/Reuters)

In this photo taken Sunday, March 12, 2017, a girl Abuk walks home with her brothers and friends after collecting clean water from a water point four kilometers away from her home, in Aweil, in South Sudan. As World Water Day approaches on March 22, more than 5 million people in South Sudan, do not have access to safe, clean water, compounding the problems of famine and civil war, according to the UNICEF. (Photo by Mackenzie Knowles-Coursin/UNICEF via AP Photo)